In general, when a tape cassette is only half inserted into an audio reproduction device, this cassette is set automatically in the play-back state. A so-called auto-reverse mechanism, which detects automatically the end of the tape, uses pinch rollers to thrust the tape on capstan journals, turning in opposite directions in order to move this tape in the backward direction and continue the play-back state. Further, it is so constructed that the fast forward (FF) operation (by which the capstan journals and the pinch roller thrusted thereon are kept away from each other and the rotation of the reel mechanism is increased), the rewinding (REW) operation, (the fast forward reproducing (QUE) operation (where the tape is forwarded with a high speed while reproduced sound is generated), the backward reproducing (REVEW) operation while reproduced sound is generated, etc. are possible. In addition, it is so constructed that these mechanisms and operations are performed by combining various means such as gear mechanisms, cam mechanisms, etc., starting from the rotation of a driving motor turning only in one direction.